// interfaces/Games.java
// (c)2016 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://OnJava8.com for more book information.
// A Game framework using Factory Methods

interface Game { boolean move(); }
interface GameFactory { Game getGame(); }

class Checkers implements Game {
  private int moves = 0;
  private static final int MOVES = 3;
  @Override
  public boolean move() {
    System.out.println("Checkers move " + moves);
    return ++moves != MOVES;
  }
}

class CheckersFactory implements GameFactory {
  @Override
  public Game getGame() { return new Checkers(); }
}

class Chess implements Game {
  private int moves = 0;
  private static final int MOVES = 4;
  @Override
  public boolean move() {
    System.out.println("Chess move " + moves);
    return ++moves != MOVES;
  }
}

class ChessFactory implements GameFactory {
  @Override
  public Game getGame() { return new Chess(); }
}

public class Games {
  public static void playGame(GameFactory factory) {
    Game s = factory.getGame();
    while(s.move())
      ;
  }
  public static void main(String[] args) {
    playGame(new CheckersFactory());
    playGame(new ChessFactory());
  }
}
/* Output:
Checkers move 0
Checkers move 1
Checkers move 2
Chess move 0
Chess move 1
Chess move 2
Chess move 3
*/